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Saturday, May 25, 2013
With several steps in the clotting process, there are many things that can go wrong. These conditions can be inherited, acquired, or a combination of both. Blood clotting can be separated into two main categories, bleeding problems and clotting problems.
Bleeding problems occur when part of the clotting system doesn’t work, and you bleed more easily. With an injury, for example, someone with a bleeding problem can lose more blood than another person with the same injury. Certain conditions can be inherited, meaning that you received a gene from your parents that impairs a part of the clotting system, leading to a greater tendency to bleed.
Hemophilia is an example of an inherited bleeding disorder. In this rare condition, there is a defect in the clotting cascade that causes you to bleed too much. Von Willebrand Disease, the most common kind of bleeding disorder is another kind of inherited bleeding problem caused by a defect in the clotting factor that helps platelets stick together. In the United States, 1.4 million people (about 1 in 100) have Von Willebrand Disease.
Bleeding problems can also be acquired. Aspirin can be used to treat headaches and other aches and pains, and can also help in the prevention of a heart attack. However, being on a daily dose of Aspirin can increase your bleeding risk. Aspirin interferes with the clumping action of platelets, reducing the blood’s ability to clot. While this is helpful in avoiding unwanted clots that could lead to heart attack, it can also lead to problems like internal bleeding. Other kinds of acquired bleeding disorders are platelet diseases, liver disease, and vitamin K deficiency.
Clotting problems occur when your blood has an increased tendency to clot. Just like bleeding disorders, clotting disorders can be either inherited or acquired. Inherited conditions include gene defects which cause either increased clotting or defects that prevent normal clot breakdown.
Acquired clotting disorders include risk factors that are common in many people such as:
Each of these risk factors can lead to serious, sometimes life-threatening, complications due to clot formation inside the blood vessels. Sometimes a clot can form on the inside of the vein system, which returns blood to the heart. Clots can also form in the artery system which takes oxygenated blood away from the heart to all parts of the body. Whether in the vein or artery system these internal clots can to significant harm. Damage can occur both at the site where the clot forms and in other parts of the body if part of the clot breaks off and travels through the blood vessel system. The original clot is called a “thrombus.” A clot that breaks off is called an “embolus.” An embolus moves through the bloodstream, and can get lodged in a vessel at a distant site, blocking blood flow and causing damage. The specific parts of the body at risk depend on whether the original clot is in the vein system or artery system. The major risk for clots in the vein system is a pulmonary embolus. Clots in the artery system put people at risk for heart attack and stroke.
In deep vein thrombosis (DVT) a blood clot forms in a deep vein. Any of the risk factors just mentioned can lead to this problem. The clot can block normal blood flow, resulting in swelling and pain. While there can be local long-term complications such as skin discoloration, ongoing swelling and ulcers, the primary risk of DVT is “pulmonary embolism.” In this situation, part of the vein blood clot (most commonly in the leg or pelvis) breaks off and travels to the lung. If the embolus is small, it may not cause problems. However, if it is big enough it can partially, or completely, block blood vessels in the lung and can lead to death.
People at risk for blood clots can form clots in arteries and well as veins. People with risk factors described above are at significant risk for atherosclerosis throughout the artery system. Atherosclerotic plaque can grow within blood vessels and gradually decrease blood flow causing serious problems throughout the body including, heart, brain, eyes, legs/feet, and kidney. Atherosclerotic plaque can rupture causing a blood clot to form. This can cause sudden blockage of the vessel at the site and can lead to conditions such as heart attack and stroke. A ruptured plaque with clot formation can also result in embolism causing stroke or blocking vessels in other parts of the body such as limbs, kidney, and digestive system.
In talking about clotting problems it is important to mention a particular condition called atrial fibrillation. In people with atrial fibrillation their hearts beat with an irregular rhythm. It is the most common heart rhythm problem. The American Heart Association estimates that 2.7 million people in the United States are living with the condition. Having atrial fibrillation dramatically increases risk of clot formation in the heart itself which can result in embolism. Having it increases the risk of a clot related stroke by five times.
This article is a NetWellness exclusive.
Last Reviewed: May 01, 2012
Susan Wentz, MD, MS
Director, Area Health Education Center
School of Medicine
Case Western Reserve University